The new season of Lost Notes will be here in September. Meantime, this summer, we’re sharing a couple of bonus episodes. Fifty years ago, an unlikely musical group evolved out of the Oakland chapter of the Black Panther Party. They were called The Lumpen. And although they quickly gained a following for their air-tight funk, they were always meant to be much more than mere entertainment. Peter Gilstrap reports on the rise and fall of an unlikely R&B group born out of social upheaval.